[FPSPACE] The odds of getting hit by a space rock
epgrondine at hotmail.com
Wed Mar 28 17:39:39 EST 2007
I have written a book summarizing the impact history in the Americas for the
last 10,000 years:
Man and Impact in the Americas.
Bottom line: Over the last 6,000,000 years man has nearly gone the way of
the dinosaur several times.
The last 10,000 years were dominated by the impact of fragments of Comet
Encke. Globally, we've seen impact mega-tsunami about 1 per 1,000 years,
and tunguska type blasts about 1 per 100 years.
I don't know if this represents the long term situation or if we are just
entering a period of higher than normal cometary activity, viz also comets
Shoemaker Levy 9 and Schwassmann Wachmann 3. Morrison's numbers for asteroid
impact appear about right, but the impact hazard is composed of asteroid
impacts and comet impacts.
My book is $34.95 through amazon, or contact me off list and we'll work
something out. As its about 546 pages, please excuse me if I don't type the
whole thing out here for you.
Man and Impact in the Americas
>From: DSFPortree at aol.com
>To: ljk4 at msn.com, fpspace at friends-partners.org
>Subject: Re: [FPSPACE] The odds of getting hit by a space rock
>Date: Wed, 28 Mar 2007 11:57:49 EDT
>And, of course, some fishermen and woodcutters were killed by the Tunguska
>impact. I haven't been able to locate a reliable figure on the number of
>David S. F. Portree
>author & educator
>dsfportree at aol.com
>Flagstaff Arizona USA
>"It's like when you're a kid, the first time they tell you that the world's
>turning and you just can't quite believe it because everything looks like
>standing still. I can feel it - the turn of the Earth. The ground beneath
>feet is spinning at a thousand miles an hour, the entire planet is hurtling
>around the Sun at sixty-seven thousand miles an hour, and I can feel it.
>falling through space, you and me. Clinging to the skin of this tiny little
>world, and if we let go..." - The Ninth Doctor
> AOL now offers free email to everyone.
> Find out more about what's free from AOL at http://www.aol.com.
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